U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Publication Year 2019 Remove constraint Publication Year: 2019 Subject term chelation Remove constraint Subject term: chelation
Start Over

Search

246  Search Results

« Previous | 1 - 50 of 246 |
Number of results to display per page

Search Results

1. 1,1-Phosphinoboration of diazomethanes

Author:
Alina Trofimova; James H. W. LaFortune; Zheng-Wang Qu; Stephen A. Westcott; Douglas W. Stephan
Source:
Chemical communications 2019 v.55 no.80 pp. 12100-12103
ISSN:
1364-548X
Subject:
boron; chelation; heterocyclic compounds; zwitterions
Abstract:
... The reactions of the phosphinoboranes Ph₂PBMes₂, Ph₂PBpin, and Ph₂PBcat with the diazomethanes Ph₂CN₂, C₁₂H₈CN₂, and EtO₂CCHN₂ are shown to give products of 1,1-phosphinoboration. The products (1–6) are shown to have PNB linkages with three-coordinate boron centers, whereas the products (EtOOC)CNN(PR₂)(Bpin) (R = Ph 7, tBu 8) form zwitterionic heterocycles resulting from chelation of the ester car ...
DOI:
10.1039/c9cc06914c

2. Acute barium poisoning in a dog after ingestion of handheld fireworks (party sparklers)

Author:
Monique K. Stanley; Kylie Kelers; Elise Boller; Manuel Boller
Source:
Journal of veterinary emergency and critical care 2019 v.29 no.2 pp. 201-207
ISSN:
1479-3261
Subject:
barium; barium nitrate; blood serum; chelation; dogs; females; fluid therapy; heart; hypokalemia; ingestion; magnesium sulfate; mass spectrometry; muscles; normal values; pH; paralysis; poisoning; potassium; potassium chloride
Abstract:
... OBJECTIVE: To report a case of acute barium poisoning in a dog subsequent to ingestion of a common handheld pyrotechnic (sparkler). CASE SUMMARY: A 5‐year‐old female neutered German Shorthaired Pointer presented with acute onset of generalized flaccid muscle paralysis and fasciculations, ptyalism, and an irregular heart rhythm. Marked hypokalemia (1.9 mmol/L [mEq/L]; reference range [3.5–5.8 mmol/ ...
DOI:
10.1111/vec.12820

3. Adsorption mechanism of alkyl hydroxamic acid onto bastnäsite: Fundamental steps toward rational collector design for rare earth elements

Author:
Anna K. Wanhala; Benjamin Doughty; Vyacheslav S. Bryantsev; Lili Wu; Shannon M. Mahurin; Santa Jansone-Popova; Michael C. Cheshire; Alexandra Navrotsky; Andrew G. Stack
Source:
Journal of colloid and interface science 2019 v.553 pp. 210-219
ISSN:
0021-9797
Subject:
Fourier transform infrared spectroscopy; adsorption; bastnaesite; calcite; calcium carbonate; calorimetry; cations; cerium; chelation; density functional theory; enthalpy; ligands; metal ions; moieties; titration
Abstract:
... Rare earth element (REE) production is limited in part by inefficient strategies for beneficiation. Hydroxamic acid ligands are promising reagents for the selective flotation of bastnäsite [(Ce,La)FCO₃], a major REE ore mineral, but the mechanism and energetics of adsorption are not understood, interfering with the design of new, more efficient reagents. Here, the adsorption of octyl hydroxamic ac ...
DOI:
10.1016/j.jcis.2019.06.025

4. Advances in the antimicrobial and therapeutic potential of siderophores

Author:
Marta Ribeiro; Manuel Simões
Source:
Environmental chemistry letters 2019 v.17 no.4 pp. 1485-1494
ISSN:
1610-3653
Subject:
antibiotics; bacterial growth; biosynthesis; chelation; drug therapy; environmental science; iron; siderophores; starvation; virulence
Abstract:
... The increasing bacterial resistance from antibiotic overuse has fostered the search for novel antimicrobial strategies. In particular, bacterial systems involving iron (Fe) uptake are studied to develop new therapeutics against infectious diseases, because iron is crucial for bacterial growth and is a main virulence factor for infection. Iron assimilation is commonly based on the production of sid ...
DOI:
10.1007/s10311-019-00887-9

5. Advancing Chelation Chemistry for Actinium and Other +3 f-Elements, Am, Cm, and La

Author:
Benjamin W. Stein; Amanda Morgenstern; Enrique R. Batista; Eva R. Birnbaum; Sharon E. Bone; Samantha K. Cary; Maryline G. Ferrier; Kevin D. John; Juan Lezama Pacheco; Stosh A. Kozimor; Veronika Mocko; Brian L. Scott; Ping Yang
Source:
Journal of the American Chemical Society 2019 v.141 no.49 pp. 19404-19414
ISSN:
1520-5126
Subject:
X-ray absorption spectroscopy; actinium; cations; chelating agents; chelation; encapsulation; ligands; nuclear magnetic resonance spectroscopy; technology
Abstract:
... A major chemical challenge facing implementation of ²²⁵Ac in targeted alpha therapy—an emerging technology that has potential for treatment of disease—is identifying an ²²⁵Ac chelator that is compatible with in vivo applications. It is unclear how to tailor a chelator for Ac binding because Ac coordination chemistry is poorly defined. Most Ac chemistry is inferred from radiochemical experiments ca ...
DOI:
10.1021/jacs.9b10354

6. Alginate-graphene oxide hydrogels with enhanced ionic tunability and chemomechanical stability for light-directed 3D printing

Author:
Thomas M. Valentin; Alexander K. Landauer; Luke C. Morales; Eric M. DuBois; Shashank Shukla; Muchun Liu; Lauren H. Stephens Valentin; Christian Franck; Po-Yen Chen; Ian Y. Wong
Source:
Carbon 2019 v.143 pp. 447-456
ISSN:
0008-6223
Subject:
carbon; chelation; crosslinking; deformation; energy; hydrogels; hydrogen bonding; marine environment; modulus of elasticity; nanocomposites; nanosheets; oils
Abstract:
... Nanocomposite hydrogels that incorporate 2D carbon nanomaterials could enable augmented and responsive behaviors not observed with polymeric matrices alone. In particular, non-covalent interactions could facilitate enhanced mechanical performance that can be self-recovered with external stimuli. Here, we demonstrate alginate-graphene oxide (GO) hydrogels using a non-covalent, ionic crosslinking me ...
DOI:
10.1016/j.carbon.2018.11.006

7. Ambiguity of NRPS Structure Predictions: Four Bidentate Chelating Groups in the Siderophore Pacifibactin

Author:
Clifford D. Hardy; Alison Butler
Source:
Journal of natural products 2019 v.82 no.4 pp. 990-997
ISSN:
1520-6025
Subject:
Alcanivorax; bioinformatics; biosynthesis; chelation; enzymes; gallium; genome mining; iron; ligands; multigene family; nuclear magnetic resonance spectroscopy; peptides; photochemical reactions; prediction; siderophores; titration
Abstract:
... Identified through a bioinformatics approach, a nonribosomal peptide synthetase gene cluster in Alcanivorax pacificus encodes the biosynthesis of the new siderophore pacifibactin. The structure of pacifibactin differs markedly from the bioinformatic prediction and contains four bidentate metal chelation sites, atypical for siderophores. Genome mining and structural characterization of pacifibactin ...
DOI:
10.1021/acs.jnatprod.8b01073

8. Amelioration of cadmium stress in Withania somnifera by ROS management: active participation of primary and secondary metabolism

Author:
Bhawana Mishra; Neelam Singh Sangwan
Source:
Plant growth regulation 2019 v.87 no.3 pp. 403-412
ISSN:
0167-6903
Subject:
NAD (coenzyme); NADP (coenzyme); Withania somnifera; aspartate transaminase; beta-fructofuranosidase; biochemical pathways; cadmium; carbon; chelation; cinnamyl alcohol dehydrogenase; dihydrolipoyl dehydrogenase; enzyme activity; esterases; flavonoids; glutathione transferase; heavy metals; medicinal properties; metabolism; ornithine-oxo-acid transaminase; phenolic compounds; proline; reactive oxygen species; reducing sugars; shikimate dehydrogenase; therapeutics; toxicity
Abstract:
... Cadmium (Cd) is considered as a non-essential heavy metal with substantial toxicity on environment. Withania somnifera, a reputed therapeutic herb exhibits vast pharmacological activities due to the presence of steroidal lactones-withanolides. The present study deals with reactive oxygen species (ROS) management through primary and secondary metabolism as adaptive response, on exogenous Cd exposur ...
DOI:
10.1007/s10725-019-00480-8

9. Amido-functionalized carboxymethyl chitosan/montmorillonite composite for highly efficient and cost-effective mercury removal from aqueous solution

Author:
Hehua Zeng; Lan Wang; Dan Zhang; Fu Wang; Virender K. Sharma; Chuanyi Wang
Source:
Journal of colloid and interface science 2019 v.554 pp. 479-487
ISSN:
0021-9797
Subject:
adsorbents; adsorption; aqueous solutions; biopolymers; chelation; chitosan; clay; composite materials; cost effectiveness; industrial wastewater; ions; mercury; montmorillonite; polyethyleneimine; remediation; China
Abstract:
... The efficient and cost-effective removal of mercury (Hg) from water is highly desired. A biopolymer/clay composite adsorbent was developed by introducing montmorillonite modified with sulfhydryl into a hyperbranched polyethylenimine functionalized carboxymethyl chitosan matrix (HPFC/MT-S), which proves to be a superior alternative for the removal of Hg(II) ions from aqueous solutions. The develope ...
DOI:
10.1016/j.jcis.2019.07.029

10. Aminochelates in plant nutrition: a review

Author:
Mohammad Kazem Souri; Mansoure Hatamian
Source:
Journal of plant nutrition 2019 v.42 no.1 pp. 67-78
ISSN:
1532-4087
Subject:
adverse effects; amino acids; chelates; chelating agents; fertilizer application; ions; nitrogen; nitrogen fertilizers; plant nutrition; plant tissues; soil; urea
Abstract:
... Chelates are compounds that are applied to improve nutrition, especially the micronutrients status of plant tissues. During past decades, various chelating agents have been synthesized and introduced to agricultural systems. The recent formulas are aminochelates that are synthesized using various amino acids and a single or several nutrient ions aimed at improving fertilizer use efficiency and mor ...
DOI:
10.1080/01904167.2018.1549671

11. Antioxidant Activity of Collagen Extracts Obtained from the Skin and Gills of Oreochromis sp.

Author:
José Roberto Medina-Medrano; Tannia Alexandra Quiñones-Muñoz; Abel Arce-Ortíz; Juan Gabriel Torruco-Uco; Ricardo Hernández-Martínez; Manuel Alejandro Lizardi-Jiménez; Elizabeth Varela-Santos
Source:
Journal of medicinal food 2019 v.22 no.7 pp. 722-728
ISSN:
1557-7600
Subject:
2,2-diphenyl-1-picrylhydrazyl; Oreochromis; active ingredients; antioxidant activity; ascorbic acid; chelating agents; chelation; chemical analysis; collagen; dietary supplements; drugs; evisceration; filleting; flour; free radical scavengers; functional foods; galls; hydrolysis; metal ions; pepsin; raw materials; silage; value-added products; wastes
Abstract:
... Efforts aimed at reduction of fishing waste generated during the evisceration and filleting are scarce. The fishing waste is used in the production of low value-added products, such as flours or silages. It is important to visualize an alternative and profitable use of this waste, as it constitutes a serious environmental problem. This research determined the antioxidant properties of collagenous ...
DOI:
10.1089/jmf.2019.0013

12. Antioxidant efficiency and mechanisms of green tea, rosemary or maté extracts in porcine Longissimus dorsi subjected to iron-induced oxidative stress

Author:
Feibai Zhou; Sisse Jongberg; Mouming Zhao; Weizheng Sun; Leif H. Skibsted
Source:
Food chemistry 2019 v.298 pp. 125030
ISSN:
0308-8146
Subject:
antioxidants; chelation; dose response; free radicals; green tea; hydrophilicity; hydrophobicity; lipid peroxidation; longissimus muscle; myoglobin; oxidation; oxidative stress; oxygen consumption; plant extracts; quinones; rosemary; swine; thiobarbituric acid-reactive substances; thiols
Abstract:
... Plant extracts from rosemary (RE), green tea (GTE), and maté (ME) were compared for the protection against iron-induced oxidation in porcine homogenates at total phenolic concentrations from 25 to 250 ppm. Lipid oxidation as indicated by TBARS was in all cases sufficiently suppressed, especially for RE. Hydrophobic RE retarded overall oxidation in the homogenates with an inverted dose-dependent re ...
DOI:
10.1016/j.foodchem.2019.125030

13. Antioxidant properties of phenolic surrogates of lignin depolymerisation

Author:
Laëtitia Cesari; Fabrice Mutelet; Laetitia Canabady-Rochelle
Source:
Industrial crops and products 2019 v.129 pp. 480-487
ISSN:
0926-6690
Subject:
antioxidant activity; antioxidants; biofuels; biomass; chelation; copper; depolymerization; guaiacol; industry; iron; lignin; p-cresol; phenol; pyrocatechol; straw; vanillin; wood
Abstract:
... The thermochemical conversion of biomass (wood, straw, etc.) provides bio-oils containing some molecules with antioxidant properties and used in pharmaceutical or cosmetic industries. In this work, five different antioxidant tests were performed on eight phenolic surrogates of lignin depolymerisation mostly found in lignin bio-oils: phenol, guaiacol, syringol, pyrocatechol, o-, m-, p-cresol and va ...
DOI:
10.1016/j.indcrop.2018.12.010

14. The Arabidopsis defensin gene AtPDF2.5 mediates cadmium tolerance and accumulation

Author:
Jin‐Song Luo; Yong Yang; Tianyu Gu; Zhimin Wu; Zhenhua Zhang
Source:
Plant, cell and environment 2019 v.42 no.9 pp. 2681-2695
ISSN:
0140-7791
Subject:
Arabidopsis thaliana; cadmium; cell walls; chelation; cysteine; genes; protoplasts; rice; site-directed mutagenesis; vascular bundles; xylem
Abstract:
... Although excess cadmium (Cd) accumulation is harmful to plants, the molecular mechanisms underlying Cd detoxification and accumulation in Arabidopsis thaliana remain largely undetermined. In this study, we demonstrated that the A. thaliana PLANT DEFENSIN 2 gene AtPDF2.5 is involved in Cd tolerance and accumulation. In vitro Cd‐binding assays revealed that AtPDF2.5 has Cd‐chelating activity. Site‐d ...
DOI:
10.1111/pce.13592

15. Arsenic detoxification in Eucalyptus: subcellular distribution, chemical forms, and sulfhydryl substances

Author:
Weisheng Wang; Min Meng; Lei Li
Source:
Environmental science and pollution research international 2019 v.26 no.24 pp. 24372-24379
ISSN:
0944-1344
Subject:
Eucalyptus grandis; Eucalyptus urophylla; acreage; adsorption; arsenic; cell walls; chelation; ethanol; glutathione; heavy metals; hybrids; hydroponics; leaves; phytochelatins; polluted soils; roots; sodium chloride; thiols; vacuoles; China
Abstract:
... The Eucalyptus cultivation acreage was large in Guangxi provinces. Guanglin 9 (Eucalyptus grandis × Eucalyptus urophylla) is a widely cultivated Eucalyptus species and has been found to grow normally in soils contaminated by heavy metals such as arsenic (As), but the detoxification mechanisms are not clear yet. Through hydroponic experiment, the adsorption and detoxification of As in Eucalyptus we ...
DOI:
10.1007/s11356-019-05701-1

16. Augmenting the adsorption parameters of palladium onto pyromellitic acid-functionalized nanosilicas from aqueous solution

Author:
Jiling Zhao; Chen Wang; Shixing Wang; Libo Zhang; Bing Zhang
Source:
Colloids and surfaces 2019 v.578 pp. 123581
ISSN:
0927-7757
Subject:
Fourier transform infrared spectroscopy; X-ray photoelectron spectroscopy; adsorbents; adsorption; anhydrides; aqueous solutions; chelation; electrostatic interactions; equations; heat production; industrial wastewater; ions; nanomaterials; pH; palladium; scanning electron microscopy; silica; sorption isotherms; transmission electron microscopy
Abstract:
... Many industrial wastewaters contain large amounts of palladium and the recovery of palladium from wastewater has great significance. Here, a new adsorbent (PMA-SNP) was synthesized by modifying nano-silica with pyromellitic anhydride to selectively adsorb Pd(II) in wastewater. Fourier transform infrared spectroscopy, scanning electron microscopy, Brunauer–Emmett–Teller equation, X-ray photoelectro ...
DOI:
10.1016/j.colsurfa.2019.123581

17. Azepine derivative T4FAT, a new copper chelator, inhibits tyrosinase

Author:
Sayaka Okajima; Akie Hamamoto; Masataka Asano; Kenta Isogawa; Hironari Ito; Shinya Kato; Yoko Hirata; Kyoji Furuta; Hiroshi Takemori
Source:
Biochemical and biophysical research communications 2019 v.509 no.1 pp. 209-215
ISSN:
0006-291X
Subject:
catalytic activity; chelating agents; chelation; copper; cosmetics; dihydroxyphenylalanine; enzyme activity; enzyme inhibition; gene expression; gene expression regulation; hydroxylation; hyperpigmentation; kojic acid; melanin; melanogenesis; melanoma; messenger RNA; mice; monophenol monooxygenase; mushrooms; protein synthesis; quinones; toxicity; tyrosine; ultraviolet radiation
Abstract:
... Melanin plays an important role in the protection of the skin from ultraviolet irradiation. However, excessive melanin deposition leads to hyperpigmentation and freckles, which are recognized as skin problems, and signs of aging. Tyrosinase, a copper-containing protein, is the rate-limiting enzyme in melanin biosynthesis and first catalyzes the hydroxylation of l-tyrosine to 3,4-dihydroxyphenylala ...
DOI:
10.1016/j.bbrc.2018.12.105

18. Bioactivity of hydrolysates obtained from bovine casein using artichoke (Cynara scolymus L.) proteases

Author:
E. Bueno-Gavilá; A. Abellán; F. Girón-Rodríguez; J.M. Cayuela; E. Salazar; R. Gómez; L. Tejada
Source:
Journal of dairy science 2019 v.102 no.12 pp. 10711-10723
ISSN:
0022-0302
Subject:
2,2-diphenyl-1-picrylhydrazyl; Cynara cardunculus subsp. cardunculus; Enterococcus faecalis; antimicrobial properties; antioxidant activity; antioxidants; artichokes; aspartic proteinases; casein; casein hydrolysates; cattle; chelation; databases; dipeptidyl-peptidase IV; flowers; hydrolysates; hydrolysis; hydrophobicity; immunomodulation; inhibitory concentration 50; iron; molecular weight; peptides; peptidyl-dipeptidase A
Abstract:
... The objective of this work was to obtain casein hydrolysates with aspartic proteinases present in extracts from the artichoke flower (Cynara scolymus L.) and evaluate their antioxidant, antimicrobial, and angiotensin-I converting enzyme (ACE) inhibitory activity in vitro. The casein hydrolysates produced by the action of C. scolymus had elevated antihypertensive and antioxidant activity due to the ...
DOI:
10.3168/jds.2019-16596

19. Bioinspired and biomineralized magnesium oxychloride cement with enhanced compressive strength and water resistance

Author:
Qianqian Ye; Yufei Han; Shifeng Zhang; Qiang Gao; Wei Zhang; Hui Chen; Shanshan Gong; Sheldon Q Shi; Changlei Xia; Jianzhang Li
Source:
Journal of hazardous materials 2019 pp. -
ISSN:
0304-3894
Subject:
biomineralization; carbon dioxide; cement; chelation; compression strength; corn starch; crystal structure; crystals; environmental hazards; greenhouse gas emissions; hydrogen bonding; industry; ions; magnesium; moieties; polyacrylic acid; sodium
Abstract:
... High CO2 emissions during the production process of ordinary Portland cement (OPC) promoted greener-cement development, wherein the application of magnesium oxychloride cement (MOC) can add value to waste in potash industry and reduce environmental hazards. However, its application was restricted by its inferior water resistance. It’s a challenge to remarkably increase both the compressive strengt ...
DOI:
10.1016/j.jhazmat.2019.121099

20. Biosorption behavior of the Ochrobactrum MT180101 on ionic copper and chelate copper

Author:
Huanlong Peng; Da Li; Jian Ye; Haixing Xu; Wenjia Xie; Yuguang Zhang; Meirou Wu; Liang Xu; Yongmei Liang; Wei Liu
Source:
Journal of environmental management 2019 v.235 pp. 224-230
ISSN:
0301-4797
Subject:
Ochrobactrum; X-ray photoelectron spectroscopy; bacteria; biosorption; biotransformation; chelating agents; chelation; copper; heavy metals; pH; thermodynamics
Abstract:
... To study the biosorption behaviors of bacteria on heavy metal chelators, the biosorption kinetics, biosorption thermodynamics and pH influence tests of the Ochrobactrum MT180101 on ionic and chelate copper were investigated. Furthermore, the biosorption mechanisms of the Ochrobactrum MT180101 on ionic copper and chelate copper were explained by means of an excitation emission matrix as well as inf ...
DOI:
10.1016/j.jenvman.2019.01.060

21. Built to bind: biosynthetic strategies for the formation of small-molecule protease inhibitors

Author:
Leonard Kaysser
Source:
Natural product reports 2019 v.36 no.12 pp. 1654-1686
ISSN:
1460-4752
Subject:
Lewis acids; Lewis bases; active sites; biosynthesis; chelation; diabetes; genome; hypertension; medicine; metalloproteinases; peptides; thrombosis
Abstract:
... Covering: up to 2019 Inhibitors of proteases and related enzymes have versatile applications in medicine and other areas. They are used in the clinic e.g. for the treatment of cancer, hypertension, thrombosis, diabetes as well as viral and bacterial infections. Most of these drugs are produced synthetically but a substantial part of them has been developed from or are inspired by natural products. ...
DOI:
10.1039/c8np00095f

22. Calcium ion incorporated hydrous iron(III) oxide: synthesis, characterization, and property exploitation towards water remediation from arsenite and fluoride

Author:
Abir Ghosh; Suparna Paul; Sayan Bhattacharya; Palani Sasikumar; Krishna Biswas; Uday Chand Ghosh
Source:
Environmental science and pollution research 2019 v.26 no.5 pp. 4618-4632
ISSN:
0944-1344
Subject:
adsorption; arsenic; arsenites; atomic force microscopy; calcium; chelation; entropy; fluorides; ion exchange; iron; iron oxides; models; pH; phosphates; porous media; remediation; surface area
Abstract:
... Calcium ion-incorporated hydrous iron(III) oxide (CIHIO) samples have been prepared aiming investigation of efficiency enhancement on arsenic and fluoride adsorption of hydrous iron(III) oxide (HIO). Characterization of the optimized product with various analytical tools confirms that CIHIO is microcrystalline and mesoporous (pore width, 26.97 Å; pore diameter, 27.742 Å with pore volume 0.18 cm³ g ...
DOI:
10.1007/s11356-018-3872-3

23. Carboxyl Fe3O4 magnetic nanoparticle-based SPE and HPLC method for the determination of six tetracyclines in water

Author:
Yi Yang; Shuo Yin; Danni Yang; Yang Jiang; Yongxin Li; Chen Zhou; Chengjun Sun
Source:
Analytical and bioanalytical chemistry 2019 v.411 no.2 pp. 507-515
ISSN:
1618-2642
Subject:
acetonitrile; adsorbents; chelation; chemical species; chlortetracycline; demeclocycline; doxycycline; electrostatic interactions; high performance liquid chromatography; ions; iron; iron oxides; lakes; magnetism; methanol; oxalic acid; oxytetracycline; river water; solid phase extraction; tap water; tetracycline; wavelengths
Abstract:
... A novel carboxyl Fe₃O₄ magnetic nanoparticle-based solid-phase extraction combined with high-performance liquid chromatography was developed for the analysis of oxytetracycline, tetracycline, demeclocycline, metacycline, chlortetracycline, and doxycycline in water samples. Driven by the electrostatic interaction and the strong chelation between tetracyclines and iron ions, tetracyclines in samples ...
DOI:
10.1007/s00216-018-1475-y

24. Challenges in the bioanalysis of tetracyclines: Epimerisation and chelation with metals

Author:
Mark A.J. Bayliss; Katarina Rigdova; Mathew Kyriakides; Sally Grier; Andew M. Lovering; Kate Ellery; David C. Griffith; Alasdair MacGowan
Source:
Journal of chromatography 2019 v.1134-1135 pp. 121807
ISSN:
1570-0232
Subject:
EDTA (chelating agent); Gram-negative bacteria; acetonitrile; ambient temperature; calcium; chelation; drugs; freezers; freezing; hemodialysis; liquid chromatography; magnesium; mass spectrometry; minocycline; tetracycline; tigecycline; toxicology; trichloroacetic acid; urine
Abstract:
... Tetracyclines (TCs) are important broad spectrum antibiotics which are active against gram-positive and gram-negative bacteria. TCs readily form epimers, especially under weakly acidic conditions. The epimers are reported to have different antibacterial and toxicological properties and pose a significant challenge for selective bioanalysis, being isobaric with the parent drug and possessing very s ...
DOI:
10.1016/j.jchromb.2019.121807

25. Changes of the stability and bioactivity of quercetin and myricetin in BGC-823 cells in response to heat treatment and Fe2+/Cu2+ addition

Author:
Wan-Ning Liu; Xin-Huai Zhao
Source:
Journal of food measurement & characterization 2019 v.13 no.4 pp. 3285-3297
ISSN:
2193-4126
Subject:
DNA damage; apoptosis; bioactive properties; chelation; copper; flow cytometry; fluorescent dyes; foods; growth retardation; heat treatment; humans; iron; myricetin; oxidative stress; quercetin; reactive oxygen species; stomach neoplasms; temperature
Abstract:
... Two flavonols quercetin and myricetin with heat treatment and Fe²⁺/Cu²⁺ addition were assessed for stability and bioactivity changes. Quercetin and myricetin at 37 °C showed higher degradation rate constants than those at 20 °C (0.133 − 1.025 vs. 0.299 − 1.803 h⁻¹). Due to the chelation of flavonol and metals, Fe/Cu addition at the two temperatures (except Cu addition at 37 °C) mostly led to enhan ...
DOI:
10.1007/s11694-019-00250-0

26. Characterization of Aspergillus niger siderophore that mediates bioleaching of rare earth elements from phosphorites

Author:
Yehia Osman; Ahmed Gebreil; Amr M. Mowafy; Tarek I. Anan; Samar M. Hamed
Source:
World journal of microbiology & biotechnology 2019 v.35 no.6 pp. 93
ISSN:
0959-3993
Subject:
Aspergillus niger; Fourier transform infrared spectroscopy; absorbance; atomic absorption spectrometry; bioleaching; cerium; chelation; ferric chloride; ferrichrome; fungi; iron; lanthanum; nuclear magnetic resonance spectroscopy; pH; plants (botany); samarium; siderophores; tetrazolium; thorium; uranium
Abstract:
... Siderophores are extra-cellular inducible compounds produced by aerobic microorganisms and plants to overcome iron insolubility via its chelation and then uptake inside the cell. This work aims to study the characteristics of siderophore that is produced by a rhizosphere-inhabiting fungus. This fungus has been morphologically and molecularly identified as Aspergillus niger with the ability to prod ...
DOI:
10.1007/s11274-019-2666-1

27. Chelating Surfaces for Oriented Human Serum Albumin Molecules

Author:
N. Tuccitto; G. M. L. Messina; G. Li-Destri; A. Wietecka; G. Marletta
Source:
Langmuir 2019 v.35 no.9 pp. 3354-3362
ISSN:
1520-5827
Subject:
adsorption; chelation; chemical bonding; copper; gold; human serum albumin; kinetics; metal ions; protein conformation; quartz crystal microbalance; spectroscopy; tripeptides
Abstract:
... Protein immobilization in a specific conformation or orientation at an interface is influenced by specific interactions with the outer layer of the surface. A strategy to build-up a complex construct which is able to orient protein molecules, based on metal-cation chelation processes, is reported. The proposed methodology implies the formation of a mercaptoundecanoic acid monolayer on a gold surfa ...
DOI:
10.1021/acs.langmuir.9b00068

28. Chelation-assisted formation of multi-yolk–shell Co₄N@carbon nanoboxes for self-discharge-suppressed high-performance Li–SeS₂ batteries

Author:
Tao Chen; Weihua Kong; Mengting Fan; Zewen Zhang; Lei Wang; Renpeng Chen; Yi Hu; Jing Ma; Zhong Jin
Source:
Journal of materials chemistry A 2019 v.7 no.35 pp. 20302-20309
ISSN:
2050-7496
Subject:
batteries; carbon; catalytic activity; cathodes; chelation; electrical conductivity; lithium; polymerization; selenium; sulfides; sulfur
Abstract:
... Selenium sulfides are considered attractive cathode materials for lithium storage due to their higher specific capacities than elemental selenium and better electrical conductivity than sulfur. However, due to the dissolution of intermediate polyselenides and polysulfides, selenium sulfides suffer from fast capacity degradation and low coulombic efficiency. Herein, we report a chelation competitio ...
DOI:
10.1039/c9ta07127j

29. Chemical modulation of siRNA lipophilicity for efficient delivery

Author:
Wanyi Tai
Source:
Journal of controlled release 2019 v.307 pp. 98-107
ISSN:
0168-3659
Subject:
albumins; bioavailability; cell membranes; chelation; drug carriers; genes; half life; hydrophilicity; lipids; lipophilicity; medicinal properties; nanoparticles; permeability; pharmacokinetics; small interfering RNA; translation (genetics)
Abstract:
... siRNA holds tremendous promise to knockdown the disease-promoting gene in any cell type that it can be delivered. The biggest challenge facing the clinical translation of siRNA is to overcome the barriers that impede the in vivo delivery. siRNA is a highly hydrophilic macromolecule with poor pharmacological properties. The critical requirement for broadening the systemic siRNA delivery is to confe ...
DOI:
10.1016/j.jconrel.2019.06.022

30. Chitosan as an antioxidant alternative to sulphites in oenology: EPR investigation of inhibitory mechanisms

Author:
Antonio Castro Marín; Marcel Culcasi; Mathieu Cassien; Pierre Stocker; Sophie Thétiot-Laurent; Bertrand Robillard; Fabio Chinnici; Sylvia Pietri
Source:
Food chemistry 2019 v.285 pp. 67-76
ISSN:
0308-8146
Subject:
acetaldehyde; chelation; chitosan; copper; electron paramagnetic resonance spectroscopy; filtration; hydroxyl radicals; iron; models; photooxidation; spoilage; storage conditions; sulfites; sulfur dioxide; white wines; winemaking
Abstract:
... The efficacy against oxidative degradation in model and sulphite-free white wines of two commercial, insoluble chitosans (one being approved for winemaking) were investigated by electron paramagnetic resonance (EPR). Both compounds at various doses significantly inhibited the formation of α-(4-pyridyl-1-oxide)-N-t-butylnitrone (4-POBN)-1-hydroxyethyl adducts under normal wine storage conditions. P ...
DOI:
10.1016/j.foodchem.2019.01.155

31. Chitosan modification persimmon tannin bioadsorbent for highly efficient removal of Pb(II) from aqueous environment: the adsorption equilibrium, kinetics and thermodynamics

Author:
Xiaojuan Li; Zhongmin Wang; Haijun Liang; Jingliang Ning; Guiyin Li; Zhide Zhou
Source:
Environmental technology 2019 v.40 no.1 pp. 112-124
ISSN:
1479-487X
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; adsorption; aqueous solutions; biomass; chelation; chitosan; electrostatic interactions; endothermy; environmental technology; equations; lead; models; mutagens; oxidation; persimmons; pollution; public health; scanning electron microscopes; sorption isotherms; thermodynamics; toxicity; wastewater treatment; zeta potential
Abstract:
... Lead (Pb) pollution has triggered a great threat to ecological system as well as public health due to its highly toxic and mutagenic properties. In this study, chitosan surface modified persimmon tannin (PT-CS) biomass composite as an environmental-friendly bioadsorbent for highly efficient removal of Pb(II) from aqueous solutions was investigated. Fourier-transform infrared spectroscopy, X-ray di ...
DOI:
10.1080/09593330.2017.1380712

32. Ciprofloxacin degradation in photo-Fenton and photo-catalytic processes: Degradation mechanisms and iron chelation

Author:
Ardhendu Sekhar Giri; Animes Kumar Golder
Source:
Journal of environmental sciences (China) 2019 v.80 pp. 82-92
ISSN:
1001-0742
Subject:
Escherichia coli; antibiotics; chelation; ciprofloxacin; death; drugs; hydrogen peroxide; hydroxyl radicals; iron; ligands; lighting; mineralization; pH; photocatalysis; piperazine; titanium dioxide
Abstract:
... Ciprofloxacin (CIP) is a broad spectrum synthetic antibiotic drug of fluoroquinolones class. CIP can act as a bidentate ligand forming iron complexes during its degradation in the photo-Fenton process (PFP). This work investigates on PFP for the degradation of CIP to understand the formation mechanism and stability of iron complexes under ultraviolet (UV)-light illumination. A comparison was made ...
DOI:
10.1016/j.jes.2018.09.016

33. Cobalt, copper and nickel-embedded chitosan/PAAS composite nanofiber mats as efficient heterogeneous catalysts for air oxidation of benzoin to benzil

Author:
Linjun Shao; Guiying Xing; Chenze Qi
Source:
Cellulose 2019 v.26 no.11 pp. 6769-6783
ISSN:
0969-0239
Subject:
active sites; air; catalysts; catalytic activity; cellulose; chelation; chitosan; cobalt; copper; ligands; nanofibers; nickel; oxidation; polyacrylic acid; scanning electron microscopy; schiff bases; sodium
Abstract:
... We have applied electrospinning technique to embed cobalt, copper and nickel catalysts inside chitosan (CS) and polyacrylic acid sodium salt (PAAS) composite nanofiber mats (M@CS/PAAS) (M = Co²⁺, Cu²⁺ and Ni²⁺) as stable heterogeneous catalysts. Scanning electron microscopic analysis shows that the resultant M@CS/PAAS composite mats are bead-free and cylindrical nanofibers with mean diameter rangi ...
DOI:
10.1007/s10570-019-02548-0

34. Cobalt, nickel and iron embedded chitosan microparticles as efficient and reusable catalysts for Heck cross-coupling reactions

Author:
Yehang Bao; Linjun Shao; Guiying Xing; Chenze Qi
Source:
International journal of biological macromolecules 2019 v.130 pp. 203-212
ISSN:
0141-8130
Subject:
active sites; alkenes; catalysts; catalytic activity; chelation; chitosan; cobalt; cross-coupling reactions; crosslinking; glutaraldehyde; iodides; iron; microparticles; nickel
Abstract:
... Cobalt, nickel and iron are efficient catalysts for numerous chemical and biological reactions, but they are hardly immobilized on solid matrixes due to their relatively weak chelation with the surface molecules. We have employed a co-electrospraying coupling with glutaraldehyde cross-linking technique to prepare cobalt (Co2+), nickel (Ni2+) and iron (Fe2+) catalyst embedded chitosan microparticle ...
DOI:
10.1016/j.ijbiomac.2019.02.143

35. Cobalt-Catalyzed C–H Iodination of Aromatic Amides with Molecular Iodine through the Use of a 2-Aminophenyloxazoline-Based Bidentate-Chelation System

Author:
Yadagiri Kommagalla; Naoto Chatani
Source:
Organic letters 2019 v.21 no.15 pp. 5971-5976
ISSN:
1523-7052
Subject:
air; amides; aniline; catalysts; catalytic activity; chelation; cobalt; iodination; iodine; moieties
Abstract:
... The cobalt-catalyzed chelation-assisted C–H iodination of aromatic amides using molecular iodine as an iodinating reagent is reported. The reaction is carried out in an atmosphere of air and uses Co(OAc)₂·4H₂O as an efficient catalyst and 4-chloro-2-(4,5-dihydrooxazol-2-yl)aniline as a directing group. The reaction shows a wide functional group tolerance. Mechanistic studies suggest that the react ...
DOI:
10.1021/acs.orglett.9b02109

36. Cold‐ and menthol‐evoked membrane potential changes in the moss Physcomitrella patens: influence of ion channel inhibitors and phytohormones

Author:
Mateusz Koselski; Piotr Wasko; Kamila Kupisz; Kazimierz Trebacz
Source:
Physiologia plantarum 2019 v.167 no.3 pp. 433-446
ISSN:
0031-9317
Subject:
Physcomitrella patens; abscisic acid; auxins; barium; calcium; calcium channels; cell membranes; chelation; chloride channels; cold; ethylene glycol tetraacetic acid; gadolinium; leaves; membrane potential; menthol; mosses and liverworts; potassium channels; proton pump; salicylic acid; strontium; temperature; zinc
Abstract:
... Microelectrode measurements carried out on leaf cells from Physcomitrella patens revealed that a sudden temperature drop and application of menthol evoked two types of different‐shaped membrane potential changes. Cold stimulation evoked spike‐type responses. Menthol depolarized the cell membrane with different rates. When it reached above 1 mV s⁻¹, the full response was recorded. Characteristic fo ...
DOI:
10.1111/ppl.12918

37. Combining ethylene diamine tetraacetic acid and high voltage pulsed discharge pretreatment to enhance short-chain fatty acids and phosphorus release from waste activated sludge via anaerobic fermentation

Author:
Xiao Ma; Jianyong Liu; Peishan Hu; Liang Wu; Lianpei Zou; Guangren Qian; Yu-You Li
Source:
Journal of cleaner production 2019 pp. -
ISSN:
0959-6526
Subject:
EDTA (chelating agent); activated sludge; carbon; chelation; chemical oxygen demand; denitrification; electric potential difference; energy costs; fatty acid composition; fermentation; hydrolysis; metal ions; phosphates; phosphorus; polymers; propionic acid; protein content; short chain fatty acids; waste utilization
Abstract:
... High voltage pulsed discharge has proved to be an efficient method for waste activated sludge pretreatment, however, the energy consumption of this pretreatment is always high, which hindered the practical application. In the present study, a combined ethylene diamine tetraacetic acid and high voltage pulsed discharge pretreatment method was firstly proposed to enhance short-chain fatty acids and ...
DOI:
10.1016/j.jclepro.2019.118252

38. Composition and In Vitro Effects of Cultivars of Humulus lupulus L. Hops on Cholinesterase Activity and Microbial Growth

Author:
Joanna Kobus-Cisowska; Daria Szymanowska-Powałowska; Oskar Szczepaniak; Dominik Kmiecik; Monika Przeor; Anna Gramza-Michałowska; Judyta Cielecka-Piontek; Małgorzata Smuga-Kogut; Piotr Szulc
Source:
Nutrients 2019 v.11 no.6 pp. -
ISSN:
2072-6643
Subject:
2,2-diphenyl-1-picrylhydrazyl; Humulus lupulus; Staphylococcus aureus; Staphylococcus epidermidis; antimicrobial properties; bioactive compounds; cellulose; chelation; chlorophyll; cholinesterase; cholinesterase inhibitors; cultivars; enzyme activity; essential oils; ethanol; flavonols; food production; food technology; health promotion; in vitro studies; iron; lipids; microbial growth; phenolic acids; polyphenols; proteins; raw materials; resins; toxicity testing; waxes
Abstract:
... Common hop (Humulus lupulus L.) has significant health-promoting properties. Hop cones contain resins, essential oils, proteins, polyphenols, lipids, waxes, and cellulose. Hop extracts include bioactive compounds such as polyphenolic compounds (phenolic acids, and flavonols), and chlorophylls. The aim of this study was to compare the pro-health potential of hop cone extracts obtained from three cu ...
DOI:
10.3390/nu11061377
PubMed:
31248112
PubMed Central:
PMC6627407

39. Comprehensive analysis of phenotype, microstructure and global transcriptional profiling to unravel the effect of excess copper on the symbiosis between nitrogen-fixing bacteria and Medicago lupulina

Author:
Minxia Chou; Yali Sun; Jieyu Yang; Yujie Wang; Yajuan Li; Guijie Yuan; Dehui Zhang; Jiamei Wang; Gehong Wei
Source:
Science of the total environment 2019 v.656 pp. 1346-1357
ISSN:
0048-9697
Subject:
Medicago lupulina; antimicrobial properties; antioxidant activity; biosynthesis; cell walls; chelation; copper; ecological restoration; ethylene; gene expression; gene expression regulation; genes; heavy metals; legumes; metal tolerance; microstructure; nitrogen-fixing bacteria; nodulation; peptides; phenotype; sequence analysis; symbiosis; transcription (genetics); ultrastructure
Abstract:
... Legume-rhizobial symbiosis plays an important role in agriculture and ecological restoration. However, knowledge of the molecular mechanisms, especially the microstructure and global transcriptional profiling, of the symbiosis process under heavy metal contamination is limited. In this study, a heavy metal-tolerant legume, Medicago lupulina, was treated with different concentrations of copper (Cu) ...
DOI:
10.1016/j.scitotenv.2018.12.005

40. Control of gypsum-dominated scaling in reverse osmosis system using carboxymethyl cellulose

Author:
Wei Yu; Di Song; Aimin Li; Hu Yang
Source:
Journal of membrane science 2019 v.577 pp. 20-30
ISSN:
0376-7388
Subject:
X-ray diffraction; anions; artificial membranes; carbonates; carboxymethylcellulose; chelation; fouling; gypsum; phosphates; reverse osmosis; scanning electron microscopy
Abstract:
... The mitigation of gypsum scaling on reverse osmosis (RO) membrane using carboxymethyl cellulose (CMC) as a green antiscalant was investigated in this study. Static test was conducted to pre-evaluate the inhibition performance and mechanism against gypsum scale using optical microscope and X-ray diffraction (XRD) as auxiliary analysis methods. The antiscaling effects in the RO system were investiga ...
DOI:
10.1016/j.memsci.2019.01.053

41. Controlling the fluoridophilicity of sulfonium boranes via chelation, Coulombic and hydrophobic effects

Author:
Haiyan Zhao; Youngmin Kim; Gyeongjin Park; Francois P. Gabbai
Source:
Tetrahedron 2019 v.75 no.9 pp. 1123-1129
ISSN:
0040-4020
Subject:
boranes; chelation; chemical bonding; crystal structure; fluorides; hydrophobicity; moieties; organic compounds; zwitterions
Abstract:
... We describe the synthesis and properties of a series of sulfonium boranes featuring a dimesitylboryl unit and a dimethylsulfonium or methylphenyl sulfonium moiety connected by an ortho- or para-phenylene linker. Acid-base and fluoride anion tritration experiments carried out in aqueous media indicate that [o-(Mes2B)C6H4(SMePh)]+ is the most Lewis acidic derivative. Structural and computational ana ...
DOI:
10.1016/j.tet.2019.01.035

42. Conversion of monosaccharides into levulinic acid/esters: impacts of metal sulfate addition and the reaction medium

Author:
Kai Sun; Lijun Zhang; Yuewen Shao; Qingyin Li; Huailin Fan; Guanggang Gao; Shu Zhang; Qing Liu; Yi Wang; Xun Hu
Source:
Journal of chemical technology and biotechnology 2019 v.94 no.11 pp. 3676-3686
ISSN:
0268-2575
Subject:
alcohols; catalysts; catalytic activity; chelation; copper sulfate; dimethyl sulfoxide; esters; ferric sulfate; fructose; glucose; hydroxymethylfurfural; levulinic acid; polymerization; potassium sulfate; sodium sulfate; sulfuric acid; zinc sulfate
Abstract:
... BACKGROUND: Inorganic salts could be used as catalysts for the effective conversion of sugars. In this study, the impacts of various metal sulfates (Na₂SO₄, K₂SO₄, MnSO₄, CoSO₄, NiSO₄, ZnSO₄, CuSO₄, Fe₂(SO₄)₃, La₂(SO₄)₃ and Ce(SO₄)₂) on the conversion of glucose/fructose to levulinic acid in varied reaction media were evaluated. RESULTS: The sulfates strongly chelated with the sugars, preventing t ...
DOI:
10.1002/jctb.6172

43. Cu2+ ion-sensitive surface on graphite electrodes

Author:
Ignacio Pedre; Lucila Paula Méndez De Leo; Graciela Alicia González
Source:
Analytical and bioanalytical chemistry 2019 v.411 no.29 pp. 7761-7770
ISSN:
1618-2642
Subject:
carbon electrodes; chelation; copper; detection limit; drinking water; electrochemistry; graphene; ions; polyacrylic acid; spectroscopy; voltammetry
Abstract:
... A new electrochemical interface based on polyacrylic acid (PAAcid) immobilized in a Nafion® polymeric matrix on graphite screen-printed electrodes for detecting copper is presented. The copper is retained in the surface due to the capacity of the polyacid to chelate metals, and quantified using square wave voltammetry. The response was characterized by spectroscopic techniques (UV-vis-IR), which c ...
DOI:
10.1007/s00216-019-02142-0

44. Cupric ion functionalized polydopamine coated magnetic microspheres as solid-phase adsorbent for the extraction of purines in plasma

Author:
Dong-Dong Zhou; Qian Zhang; Hao Zhang; Yin-Zhen Wang; Feng-Qing Yang; Sheng-Peng Wang; Yi-Tao Wang
Source:
Journal of chromatography 2019 v.1120 pp. 95-103
ISSN:
1570-0232
Subject:
Fourier transform infrared spectroscopy; adenine; adsorbents; catechol; chelation; chromatography; copper; energy-dispersive X-ray analysis; guanine; hypoxanthine; intragastric administration; ionic strength; magnetism; microparticles; models; pH; rats; scanning electron microscopes; thermogravimetry; transmission electron microscopy; xanthine
Abstract:
... In this paper, Cu2+ functionalized Fe3O4@polydopamine core-shell (Fe3O4@PDA@Cu2+) magnetic microspheres were prepared by the chelation between Cu2+ and catechol of polydopamine surface. The synthetic magnetic adsorbent was characterized by Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, scanning electron micr ...
DOI:
10.1016/j.jchromb.2019.04.054

45. Dephytinizing and Probiotic Potentials of Saccharomyces cerevisiae (NCIM 3662) Strain for Amelioration of Nutritional Quality of Functional Foods

Author:
Kumar Raja Puppala; V Ravi Kumar; Jayant Khire; Mahesh Dharne
Source:
Probiotics and antimicrobial proteins 2019 v.11 no.2 pp. 604-617
ISSN:
1867-1306
Subject:
Eleusine coracana subsp. coracana; Saccharomyces cerevisiae; antinutritional factors; chelation; chickpeas; choloylglycine hydrolase; feeds; fermenters; food technology; functional foods; gastric acid; hydrophobicity; nutritive value; phytases; phytic acid; poultry; probiotics; soy flour; yeasts
Abstract:
... Increase of undigested complexes of phytic acid in food is gaining serious attention to overcome nutritional challenges due to chelation effects. We investigated soil-borne yeast phytase from Saccharomyces cerevisiae (NCIM 3662) for dephytinization of foods, probiotic properties, and process development. The strain produced 45 IU/DCG by cell-bound phytase in an unoptimized medium was increased fou ...
DOI:
10.1007/s12602-018-9394-y

46. Design and synthesis of thymine modified phthalocyanine for Aβ protofibrils photodegradation and Aβ peptide aggregation inhibition

Author:
Qichen Zhan; Xianqing Shi; Ting Wang; Jinhui Hu; Jiahong Zhou; Lin Zhou; Shaohua Wei
Source:
Talanta 2019 v.191 pp. 27-38
ISSN:
0039-9140
Subject:
absorption; aluminum; amyloid; brain; bromides; chelation; flow cytometry; fluorescence; iron; neurotoxicity; photochemotherapy; photolysis; photosensitizing agents; reactive oxygen species; spectroscopy; tetrazolium; thymine; transmission electron microscopy; zinc
Abstract:
... The formation and accumulation of toxic amyloid beta (Aβ) protofibrils in brain is recognized as the pathological hallmark of alzheimer’s disease (AD). Recent research indicated that photodynamic therapy (PDT) has potential to treat AD because reactive oxygen species (ROS) generated by photosensitizers (PS) could degrades Aβ protofibrils. Al³⁺ and Fe³⁺ were found at markedly high levels on and aro ...
DOI:
10.1016/j.talanta.2018.08.037

47. Designing an “Off–On” Fluorescence Sensor Based on Cluster-Based Caᴵᴵ-Metal–Organic Frameworks for Detection of l-Cysteine in Biological Fluids

Author:
Bin Yang; Xinshu Li; Jundan An; Huimin Zhang; Manman Liu; Yue Cheng; Bin Ding; Yan Li
Source:
Langmuir 2019 v.35 no.30 pp. 9885-9895
ISSN:
1520-5827
Subject:
blood serum; chelation; coordination polymers; cysteine; detection limit; dispersibility; fluorescence; humans; lead; ligands; photoluminescence
Abstract:
... Recently, luminescent metal–organic framework (MOF) materials have attracted considerable attention in fluorescence sensing. In this essay, we prepared a new cluster-based Caᴵᴵ-MOFs {[Ca₁.₅(μ₈-HL₁)(DMF)₂]·DMF}ₙ (1) with good water dispersibility, excellent photoluminescence properties (FL quantum yield of 20.37%) and great fluorescence stability. Further, it was employed to design as an “off–on” f ...
DOI:
10.1021/acs.langmuir.9b01479

48. Determination of As in honey samples by magnetic ionic liquid-based dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry

Author:
Emiliano F. Fiorentini; Brenda V. Canizo; Rodolfo G. Wuilloud
Source:
Talanta 2019 v.198 pp. 146-153
ISSN:
0039-9140
Subject:
absorbance; acetonitrile; arsenic; atomic absorption spectrometry; centrifugation; chelation; detection limit; dispersants; honey; hydrochloric acid; ionic liquids; liquid-phase microextraction; magnetic materials; magnetism; standard deviation
Abstract:
... A dispersive liquid-liquid microextraction (DLLME) method was developed based on the application of a magnetic ionic liquid (MIL) used as extractant phase for trace As determination in honey samples by electrothermal atomic absorption spectrometry (ETAAS). The procedure was simple, efficient and did not require a centrifugation stage. The As(III) species was preconcentrated by chelation with ammon ...
DOI:
10.1016/j.talanta.2019.01.091

49. Development of a new analytical method for Pb preconcentration and its further determination in water and foodstuffs using relatively low-sensitivity flame atomic absorption spectrometry

Author:
Ramazan Gürkan
Source:
International journal of environmental analytical chemistry 2019 v.99 no.10 pp. 977-995
ISSN:
1029-0397
Subject:
ascorbic acid; atomic absorption spectrometry; chelation; detection limit; food matrix; foods; lead; nonionic surfactants; pH; reference standards; rhodamines; ultrasonic treatment
Abstract:
... The present study describes chelation of Pb(II) with ascorbic acid and formation of a charge-transfer sensitive ion-pair in the presence of Rhodamine 6G at pH 5.5, and then its extraction to the micellar phase of non-ionic surfactant, PONPE 7.5 by an ultrasound-assisted cloud point extraction method before analysis by FAAS. The various variables affecting ion-pair formation and extraction efficien ...
DOI:
10.1080/03067319.2019.1617282

50. Diastereoselective sulfonate-directed carbonyl reduction of γ-keto-sulfonates

Author:
Noel McLaughlin; Colm Duffy; Francesco Alletto; Andrea Ravelli; Stefano Lancianesi; Malachi Gillick-Healy; Mauro F.A. Adamo
Source:
Tetrahedron letters 2019 v.60 no.19 pp. 1313-1316
ISSN:
0040-4039
Subject:
boron; chelation; chemical structure; diastereoselectivity; hydrides; sulfonates
Abstract:
... The diastereoselective reduction of γ-keto-sulfonates to afford α,γ-substituted γ-hydroxy sulfonates has been investigated. Herein we report the first example of a diastereoselective carbonyl reduction whereby hydride attack is directed via chelation of a neighbouring sulfonate group to a boron atom, thus affording prevalently trans γ-hydroxy sulfonates. ...
DOI:
10.1016/j.tetlet.2019.03.065